Advanced Power Converters for Energy Storage Systems for Light Traction Vehicles

Abstract:
The requirements regarding modern light traction vehicles, such as trolleybuses and tramways, gradually increase especially in the ability to operate without trolley power supply temporarily while remaining free of emissions. Efficiency, power density, volume and weight of the system become more important. At the same time, low acoustic noise and restrictive EMI-standards have to be met. The requirement to operate without trolley power supply can be met using energy storage systems based on Lithium-Ion traction batteries or super-capacitors. To fully utilize the capabilities of the storage systems, it is necessary to employ suitable power converters to manage the flow of energy in both, charging and consuming. This topic correlates to step-down and step-up DC/DC converters which have to be able to handle substantial cyclic loads at high operating temperatures. The present paper contains the results and experience gained during the development of DC/DC-converters for use with traction batteries, employed in tramways and trolleybuses.